OK, let's work through this together. We're starting with 912 and we're going to multiply it by 18, which means we add 912 to itself 18 times.
Step 1: 0 + 912 = 912
Step 2: 912 + 912 = 1824
Step 3: 1824 + 912 = 2736
Step 4: 2736 + 912 = 3648
Step 5: 3648 + 912 = 4560
Step 6: 4560 + 912 = 5472
Step 7: 5472 + 912 = 6384
Step 8: 6384 + 912 = 7296
Step 9: 7296 + 912 = 8208
Step 10: 8208 + 912 = 9120
Step 11: 9120 + 912 = 10032
Step 12: 10032 + 912 = 10944
Step 13: 10944 + 912 = 11856
Step 14: 11856 + 912 = 12768
Step 15: 12768 + 912 = 13680
Step 16: 13680 + 912 = 14592
Step 17: 14592 + 912 = 15504
Step 18: 15504 + 912 = 16416

So, 912*18 = 16416